@article{02172767,
title = {Non-orientable biembeddings of Steiner triple systems of order 15.},
journal = {Acta Mathematica Universitatis Comenianae. New Series},
volume = {73},
year = {2004},
pages = {101-106},
zbl = {1088.05018},
language = {en},
url = {http://dml.mathdoc.fr/item/02172767}
}
Bennett, G.K.; Grannell, M.J.; Griggs, T.S. Non-orientable biembeddings of Steiner triple systems of order 15.. Acta Mathematica Universitatis Comenianae. New Series, Tome 73 (2004) pp. 101-106. http://gdmltest.u-ga.fr/item/02172767/